Abstract: Objective To establish an expression system of TCR 9/ 2-Fc protein by baculovirus vector expression system and identify biological function of expressed TCR 9/ 2-Fc protein. Methods Fc and Fc gene fragments were amplified by overlap PCR and inserted into expression vector pBACp10ph. The recombinant plasmid pBACp10ph- 9/ 2(OT3)-Fc and the baculovirus DNA were co-transfected into sf9 cells. The expression position of TCR 9/ 2(OT3)-Fc was identified by Western blot and the expression efficiency of 9Fc and 2(OT3)Fc was tested by FCM. Furthermore, the binding activity of TCR 9/ 2(OT3)-Fc protein with SKOV3 cells and MNS protein was evaluated with confocal and SPR. Results The recombinant vector pBACp10ph- 9/ 2(OT3)-Fc was constructed and TCR 9/ 2(OT3)-Fc protein was expressed in sf9 cells. However, the expression efficiency of 9Fc and 2(OT3)Fc was quite different. It was proved that purified TCR 9/ 2(OT3)-Fc protein can bind with SKOV3 cell and MNS protein. Conclusions TCR 9/ 2-Fc protein is successfully expressed in baculovirus vector expression system and TCR 9/ 2-Fc protein can mimic the binding activity of TCR in vitro

Key words: TCRγ9/δ2-Fc, baculovirus vector expression system